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document cyrix configuration registers

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This commit is contained in:
deraadt 1994-08-03 21:39:16 +00:00
parent 48c91e8043
commit ffb9d6e173
1 changed files with 52 additions and 1 deletions
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53
sys/arch/i386/include/specialreg.h
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@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* from: @(#)specialreg.h 7.1 (Berkeley) 5/9/91
* $Id: specialreg.h,v 1.5 1994/05/24 11:54:24 mycroft Exp $
* $Id: specialreg.h,v 1.6 1994/08/03 21:39:16 deraadt Exp $
*/
/*
@ -52,3 +52,54 @@
#define CR0_AM 0x00040000 /* Alignment Mask (set to enable AC flag) */
#define CR0_NW 0x20000000 /* Not Write-through */
#define CR0_CD 0x40000000 /* Cache Disable */
/*
* Cyrix 486 DLC special registers, accessable as IO ports.
*/
#define CCR0 0xc0 /* configuration control register 0 */
#define CCR0_NC0 0x01 /* first 64K of each 1M memory region is non-cacheable */
#define CCR0_NC1 0x02 /* 640K-1M region is non-cacheable */
#define CCR0_A20M 0x04 /* enables A20M# input pin */
#define CCR0_KEN 0x08 /* enables KEN# input pin */
#define CCR0_FLUSH 0x10 /* enables FLUSH# input pin */
#define CCR0_BARB 0x20 /* flushes internal cache when entering hold state */
#define CCR0_CO 0x40 /* cache org: 1=direct mapped, 0=2x set assoc */
#define CCR0_SUSPEND 0x80 /* enables SUSP# and SUSPA# pins */
#define CCR1 0xc1 /* configuration control register 1 */
#define CCR1_RPL 0x01 /* enables RPLSET and RPLVAL# pins */
/* the remaining 7 bits of this register are reserved */
/*
* the following four 3-byte registers control the non-cacheable regions.
* These registers must be written as three seperate bytes.
*
* NCRx+0: A31-A24 of starting address
* NCRx+1: A23-A16 of starting address
* NCRx+2: A15-A12 of starting address | NCR_SIZE_xx.
*
* The non-cacheable region's starting address must be aligned to the
* size indicated by the NCR_SIZE_xx field.
*/
#define NCR1 0xc4
#define NCR2 0xc7
#define NCR3 0xca
#define NCR4 0xcd
#define NCR_SIZE_0K 0
#define NCR_SIZE_4K 1
#define NCR_SIZE_8K 2
#define NCR_SIZE_16K 3
#define NCR_SIZE_32K 4
#define NCR_SIZE_64K 5
#define NCR_SIZE_128K 6
#define NCR_SIZE_256K 7
#define NCR_SIZE_512K 8
#define NCR_SIZE_1M 9
#define NCR_SIZE_2M 10
#define NCR_SIZE_4M 11
#define NCR_SIZE_8M 12
#define NCR_SIZE_16M 13
#define NCR_SIZE_32M 14
#define NCR_SIZE_4G 15